This invention relates to removable jacks removably attached to the hitch of a work implement such as, for example, a round baler. More particularly, the invention relates to a jack assembly with a lock-out device. The lock-out device is constructed to render the jack operable only when the jack has been properly connected to the hitch of the work implement.
In the art of manufacturing towable work implements and other towed vehicles, such as agricultural round balers and the like, typically a tongue or hitch is connected to the main frame of the device so that the tongue or hitch can be connected to a self-propelled vehicle such as a tractor, truck, car, etc. As is commonly known, towable work implements and other towed vehicles have two or more wheels rotatably connected to the main frame so that the device can roll along firm surfaces when attached to and pulled by a self-propelled vehicle. While the tongue or hitch is connected to the self-propelled vehicle, the vehicle supports it. On the other hand, when the tongue or hitch is disengaged from the self-propelled vehicle, the tongue or hitch is free to fall to the ground. To prevent damage to the tongue or hitch, a removable jack is frequently attached to the tongue or hitch and the jack is used to move and maintain the tongue or hitch off the ground in a storage position. The jack is manufactured to be removable from the tongue or hitch so as not to interfere with the operation of the work implement or possibly get damaged during operation of the work implement. Such jacks are used, for example, with agricultural vehicles such as a round baler used for picking up hay, grass, or other cut crop material to make a bale.
One drawback to having a removable jack is that the jack can be improperly attached to the tongue or hitch due to human error. When this occurs, there is a danger that the jack will spontaneously detach and fall away from the tongue or hitch especially when the jack is adjusted by an operator. In the event that the jack detaches from the tongue or hitch during use, there is the risk that the work implement operator or bystander could be injured by the falling tongue or hitch and the falling jack. Such accidents are not uncommon and at least one European country has enacted regulations requiring that each detachable jack for a work implement, such as a round baler, be equipped with a failsafe lock-out mechanism. The failsafe lock-out mechanism ideally would render the jack operable only when the jack is properly connected and secured to the tongue or hitch of the work implement. In other words, the lock-out mechanism would render the jack inoperable when the jack is not properly connected and secured to the tongue or hitch.
The present invention endeavors to provide an improved detachable jack assembly for a towable work implement that includes a failsafe lock-out mechanism that maintains the advantages of the prior art detachable jacks while overcoming the drawbacks of the prior art devices.
Accordingly, an object of the present invention is to overcome the disadvantages of the prior art detachable jacks.
Another object of the present invention is to provide a detachable jack assembly for attaching to the tongue or hitch of a towable work implement or other towed vehicle wherein the jack assembly includes a failsafe lock-out mechanism that permits operation of the jack only when the jack is properly attached and secured to the tongue or hitch.
Another object of the present invention is to provide a detachable jack assembly for attaching to the tongue or hitch of a towable work implement or other towed vehicle wherein the jack assembly includes a failsafe lock-out mechanism that prevents operation of the jack whenever the jack is not properly attached and secured to the tongue or hitch.
Another object of the present invention is to provide a detachable jack assembly with failsafe lock-out mechanism that is simple and economical to manufacture.
Another object of the present invention is to provide a detachable jack assembly with failsafe lock-out mechanism that is durable and easy to maintain.
In accordance with the above objectives, the present invention provides in a first preferred embodiment a detachable jack assembly for attaching to a hitch of a work implement or vehicle, comprising: (a) a leg having a first member movably connected to a foot member; (b) a crank assembly disposed on the first member and having a rotatable arm, wherein the crank assembly is operably connected to the first member to move the foot member relative to the first member when the rotatable arm is rotated; (c) an attachment member disposed on the first member and configured to attach to a hitch of a work implement or vehicle, the attachment member having a pin hole formed therein; (d) a pin configured to fit in the pin hole; and (e) a lock-out assembly disposed on the attachment member, comprising a bar member biased to a first position and movable to a second position, wherein the rotation of the rotatable arm is limited by the bar member when the bar member is in the first position, and the rotatable arm moves freely when the bar member is in the second position, wherein, when the pin is disposed in the pin hole, and the bar member is in the second position, the pin maintains the bar member in the second position.
In accordance with a second embodiment, the first preferred embodiment is further modified so that the lock-out assembly further comprises a sliding ring having a main hole formed therein, and the bar member is U-shaped and includes two arm portions connected together by a central portion, wherein each arm portion is connected to the sliding ring and the sliding ring is disposed with the attachment member extending through the main hole so that the sliding ring is slidable on the attachment member.
In accordance with a third embodiment, the second preferred embodiment is further modified so that the lock-out assembly further comprises a spring disposed on each arm portion so as to bias the bar member to the first position.
In accordance with a fourth embodiment, the second preferred embodiment is further modified so that the two arm portions of the bar member straddle the first member of the leg.
In accordance with a fifth embodiment, the first preferred embodiment is further modified so that the rotatable arm rotates along a path of rotation and the bar member obstructs the path of rotation when in the first position so as to limit the movement of the rotatable arm.
In accordance with a sixth embodiment, the second preferred embodiment is modified to further comprise a base plate connected to the first member and to the attachment member, the base plate including two throughholes formed therein, wherein each throughhole is dimensioned to receive and guide one of the two arm portions that extends therethrough. Each arm portion preferably comprises a spring stop and the spring of each respective arm portion is a compressive spring disposed around the arm portion between the spring stop and the base plate.
In accordance with a seventh embodiment, the sixth preferred embodiment is further modified so that the sliding ring is disposed on the attachment member between the pin hole of the attachment member and the base plate when the bar member is in the first position.
In accordance with an eighth embodiment, the sixth preferred embodiment is further modified so that the sliding ring is disposed on the attachment member so that the pin hole is between the sliding ring and the base plate when the bar member is in the second position.
In accordance with a ninth embodiment, the first preferred embodiment is further modified so that the pin has a wide end portion dimensioned to be wider than a diameter of the pin hole to maintain the pin in the pin hole.
In accordance with a tenth embodiment, the eighth preferred embodiment is further modified so that the pin has a wide end portion dimensioned to be wider than a diameter of the pin hole, and the pin provides a stop to prevent the sliding ring from leaving the second position when the bar member is in the second position.